Mix chicken cubes, sour cream, black pepper, and soup in a mixing bowl, set aside. In a separate bow, mix, mix crushed crackers, melted butter, and poppy seeds.
In a casserole dish, put most of the cracker mixture at the bottom of the pan, saving the rest for topping. Add chicken mixture and top with the remaining cracker mixture. Bake at 350 for 30 mins. Serve over rice.